If 5EF or 4EF aren't available, you could try booking 1A for you and 2A for your partner. Then when you board, ask the person in 1K if he/she wouldn't mind swapping places with your partner. IMHO could well say yes, as 2A is nicer than 1K for a solo traveller, especially if the alternative is to listen to you in 1A calling back to your partner in 2A...